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    <meta charset="UTF-8">
    <title>JS 内置对象 - Boolean</title>
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    <h1>JS 内置对象 - Boolean</h1>
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<script>
    var b = true;

    var b = new Boolean();
    var b = new Boolean(-99);

    var b = Boolean();
    var b = Boolean(-10);
    var b = Boolean('');
    var b = Boolean(0);
    var b = Boolean(null);
    var b = Boolean(undefined);
    var b = Boolean([]);

    console.log(b);
    console.log(typeof b);
    console.log(b.constructor);
</script>
    
    

</body>
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